1. Field of the Invention
The present invention relates to a carbon nanotube based touch panel.
2. Discussion of Related Art
Following the advancement in recent years of various electronic apparatuses, such as mobile phones, car navigation systems and the like toward high performance and diversification, there has been continuous growth in the number of electronic apparatuses equipped with optically transparent touch panels at the front of their respective display devices (e.g., a display such as a liquid crystal panel). A user of any such electronic apparatus operates it by pressing or touching the touch panel with a finger, a pen, a stylus, or a like tool while visually observing the display device through the touch panel. Therefore, a demand exists for touch panels that are superior in visibility and reliable in operation.
At present, different types of touch panels, including a resistance-type, a capacitance-type, an infrared-type, and a surface sound wave-type, have been developed. Capacitance-type touch panels have several advantages, such as high accuracy and strong anti-jamming ability, and thus have been widely used.
Referring to FIGS. 5-7, a conventional capacitance-type touch panel, according to the prior art, includes a planar substrate 10, a transparent conductive layer 1 formed thereon, four metal electrodes 2a, 2b, 2c, 2d located on corners of the substrate 10 to form an equipotential surface. When a surface of the touch panel is touched by some object, such as a hand or touch pen, a coupling capacitance is formed between the object and the transparent conductive layer 1. The current then flows from the metal electrodes 2a, 2b, 2c, 2d to the touching point, to confirm the position of the touching point via calculating the ratio and the intensity of the current through the electrodes 2a, 2b, 2c, 2d. 
Generally, the transparent conductive layer 1 is an indium tin oxide (ITO) layer. However, the optically transparent conductive layer (e.g., ITO layer) is generally formed by means of ion-beam sputtering, and this method is relatively complicated. Furthermore, the ITO layer has generally poor mechanical durability, low chemical endurance and uneven resistance over an entire area of the touch panel. Additionally, the ITO layer has relatively low transparency. All the above-mentioned problems of the ITO layer tend to yield a touch panel with low sensitivity, accuracy, and brightness.
What is needed, therefore, is to provide a durable touch panel with relatively high sensitivity and precision.